Question: In $2009$, Usain Bolt set the world record for sprinting $100 \text{ m}$ in approximately $9\dfrac35$ seconds. Find his average speed in meters per second.
Explanation: To find meters per second, we divide meters by seconds. $\phantom{=}\dfrac{~~~100 \text{ meters}~~~}{9\dfrac35 \text{ seconds}}$ $ = 100 \div 9\dfrac35 $ $ = 100 \div \dfrac{48}5 $ $ = 100 \cdot \dfrac5{48} $ $ =\dfrac{500}{48} $ $ =\dfrac{125}{12} \text{ meters per second} $ Usain Bolt's speed was $\dfrac{125}{12}$ meters per second (which can be written as the mixed number $10 \dfrac{5}{12}$ if desired).